The invention relates generally to absorptive pads for internal use including surgical and wound dressings and packings, and surgical sponges and more specifically to catamenial tampons. The invention further relates to such absorptive pads intended to reduce the introduction of air into the vaginal canal with a resulting reduction in the probability of production of toxic shock syndrome exotoxin as a result of insertion of such pads and methods for production of such pads.
Toxic shock syndrome is a syndrome with a high mortality rate characterized by rapid onset of high fever, vomiting, diarrhea and rash followed by a rapid drop in blood pressure and vital organ failure. Toxic shock syndrome is associated with the presence of Staphylococcus aureus bacteria and one or more exotoxins which are produced by the bacteria. The exotoxins associated with toxic shock syndrome include Exotoxin A, B, and C, Pyrogenic Exotoxin C, Enterotoxin A, Enterotoxin B, Enterotoxin C, Staphylococcal Enterotoxin F and Toxic Shock Syndrome toxin-1. Toxic shock syndrome is not caused by the bacteria per se but rather by the toxic effects of the associated exotoxin which can pass from the vagina and other internal body cavities into the bloodstream.
Toxic shock syndrome has been found to be associated with the use of absorptive pads within the vagina which may promote the growth of bacteria and the production of exotoxin in their vicinity. The syndrome has been observed with surgical dressings but appears to be particularly associated with the use of catamenial tampons. The syndrome appears to occur with elevated frequency in association with those absorptive pads which are characterized by high levels of absorbency and which accordingly are left inside the body for extended periods. Of interest to the present invention is the observation of Robbins et al., J. Clin. Microbiol., 25, 1446-1449 (1987) that the main role of tampons in toxic shock syndrome may be that of providing a fibrous surface for heavy colonization and sufficient air for toxin production. Lee et al., J. Clin. Microbiol., 25, 87-90 (1987) suggest that elevated levels of CO.sub.2 promote toxin production.
While a preferred approach for reducing the risk of toxic shock syndrome when using absorptive pads is to frequently exchange new pads for used ones, various other approaches have been proposed by the art for reducing the risk of toxic shock syndrome associated with an internal absorbent pad. One approach is the incorporation of antibiotics or other bactericides into the absorbent pad such as described in Leveen et al., U.S. Pat. No. 5,000,749 and U.S. Pat. No. 5,070,889 which describe use of iodine bactericides in tampons and catamenial sponges. Such an approach is not always suitable for use in a catamenial product, however, because a bactericide which is active against Staphylococcus aureus can adversely affect other beneficial bacteria which make up the vaginal flora. In a related method, Lefren et al., U.S. Pat. No. 4,431,427 describes the use of catamenial tampons comprising substances such as organic acids which will maintain a pH of about 4.5 to 2.5 in the fluids absorbed during use of the tampons such that the growth of pathogenic bacteria is inhibited.
Other approaches are directed to inactivation of the toxic shock syndrome exotoxin. Jacob et al., U.S. Pat. No. 4,585,792; U.S. Pat. No. 4,722,936; and U.S. Pat. No. 4,722,937 describe the administration of L-ascorbic acid for the detoxification of the Staphylococcus aureus toxins Pyrogenic Exotoxin C and Staphylococcal Enterotoxin F. While Jacob et al. do not ascribe a mechanism for the effectiveness of ascorbic acid at neutralizing toxic shock syndrome exotoxin they observe that L-ascorbic acid is known to be a reducing agent and strong anti-oxidant and that it might operate to inactivate bacterial toxins by reducing disulfide bonds within the toxins.
Another approach is directed to the incorporation of substances within an absorbent pad which inhibit the production of toxic shock syndrome exotoxins by Staphylococcus aureus. Kass, U.S. Pat. No. 4,769,021 describes the incorporation of non-toxic divalent magnesium cations in absorptive pads in order to reduce the concentrations of available magnesium ions below those critical for optimal production of toxic shock syndrome toxin-1 and other staphylococcus products.
Of interest to the present invention are conventional tampons and inserters of various designs including those disclosed by U.S. Pat. No. 3,902,493 to Baier, et al.; U.S. Pat. No. 4,077,409 to Murray, et al.; U.S. Pat. No. 4,286,596 to Rubinstein; U.S. Pat. No. 4,413,986 to Jacobs; U.S. Pat. No. 4,431,427 to Lefren et al.; U.S. Pat. No. 4,447,222 to Sartinoranont; and U.S. Pat. No. 4,486,191 to Jacob.
Despite these developments there remains a desire in the art for absorbent pads suitable for internal use, including catamenial tampons, which are characterized by reduced risk of toxic shock syndrome.